The invention relates to an apparatus for manufacturing square inside corners on the face of a workpiece; and, more particularly, to an apparatus for making square inside corners for simulated raised panel doors as used on furniture and kitchen cabinets.
The prior art conventional raised panel door is shown in FIGS. 1 and 2. The conventional door consists of a center panel 1 and four frame parts 2, 3, 4 and 5. As shown in FIG. 2, the panel fits into a U-shaped groove, commonly referred to as a tongue-and-groove joint. Before the frame parts 2-5 are installed to panel 1, various radii 6a, 6b and chamfers 6c are cut into the parts.
The conventional raised panel door has several disadvantages. The door is expensive to manufacture because the several parts must be precisely machined in order to fit properly together. Additionally, once the door is assembled, there is a tendency for the parts of the door to separate as a result of variations in the environment, such as fluctuations in temperature and/or humidity.
It has been proposed to simulate the raised panel door by machining the various shapes from a single sheet of material, such as particle board or a medium density fiberboard. The radii and chamfers of the conventional raised panel door are reproduced in the fiberboard door using various router bits, as shown in FIG. 3. The resulting fabricated door has a similar appearance to the conventional raised panel door. The major disadvantage of this method is the inability to produce a square inside corner. As shown in FIGS. 3 and 4, the router bit used to manufacture the inside surface 6b is indicated by numeral 7. Router bit 7 is a cylindrical router bit including a circumferential curved cutting blade 8. It is clear from FIG. 4 that as router bit 7 approaches corner 9, the diameter of router bit 7 prohibits the router bit from cutting a square corner. Instead, the resulting cut includes a curved corner, the radius of which equals the radius of the router bit. This curved corner clearly evidences that the panel is simulated. One can produce the desired square corner by using a router bit which comes to a point. However, this is a long, complex and expensive process.
Accordingly, it is an object of the present invention to provide an improved apparatus for machining an interior square corner on a workpiece.
Another object of the present invention is to provide an improved apparatus for machining an interior square corner having the same appearance as a conventional raised panel door.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying drawings.